Empire

An empire is a large nation that has typically expanded by conquering or at least politically dominating other nations. The result is an ethnically and culturally diverse population that is effectively ruled by a particular ethnic/cultural group. The term "empire" stems from "imperium", a Latin term for authority (specifically to command a Roman Army).

The chief executive of an empire often carries the title of Emperor or some variation of it. However, rule by hereditary monarchy with absolute power is not necessary for a nation to be called an empire.